A reinforcing tab for reinforcing connection between a circuit board and a surface-mounted connector is for example disclosed in Japanese Unexamined Patent Publication No. 2004-319229. FIG. 10 shows a reinforcing tab 3 fixed to a connector 1 in the publication. The reinforcing tab 3 includes a fixing portion 5 fixed to the connector 1, extending portions 6 extending from the fixing portion 5 and connecting portions 4 at the ends of the extending portions 6 to be connected to a circuit board. The connecting portions 4 are bent from the extending portions 6 so as to increase a connecting area with the circuit board and maintain sufficient connecting strength.
The reinforcing tab 3 is fixed to the connector 1 such that the fixing portion 5 is received in a fixing portion 1a of a housing of the connector 1. In this condition, the bottom surfaces of the connecting portions 4 are connected with solder mounted on surfaces of lands of the circuit board. Thus, the reinforcing tab 3 reinforces the connected state of the connector 1 and the circuit board.
Such a reinforcing tab 3 is for example formed by punching and bending. FIGS. 11A to 13B show examples of the reinforcing tab 3 formed by punching and bending. In FIGS. 11A to 13B, parts having similar functions as the reinforcing tab 3 shown in FIG. 10 are designated with like reference numerals.
First, a metallic plate is stamped such that a tab base member having the shape shown in FIG. 11A is formed. Then, the connecting portions 4 are bent by applying forces as shown by arrows in FIGS. 11B and 11C. At this time, however, the connecting portions 4 will have protrusions or expansions 4b on the ends of a bent portion 4a, as shown in FIGS. 12A to 12C.
As shown in FIGS. 13A and 13B, when this connecting portion 4 is connected to a land 7 of a circuit board, a connecting surface 4c of the connecting portion is separated from the land 7 due to the protrusion 4b. As a result, a connecting area between the connecting surface 4c and the land 7 is reduced, and hence the connection between the reinforcing tab 3 and the circuit board will be degraded.